Thanks for the comment
I use Xsi to set up my model to make it hollow I don't really know how to measure the wall thickness I just make the inside model very low poly an use push filter , make it invert and merge with the high poly.
Am going to try make a video tutorial i think its better.
Wow, I really need to get to learning Blender. That looked great. I learned a long time ago the wisest thing I can do is be on my own side, be an advocate for myself and others like me. -Maya Angelou